Send INFOTYPE_LOGON to support vmconnect resize

INFOTYPE_LOGON or a variant is usually sent after the user has
successfully logged in. This triggers a hook in vmconnect that
enables automatic resizing, and also allows msrdc (the other RDP client)
to accept connections to new servers.

Author: gpotter2

common/ms-rdpbcgr.h

@@ -592,6 +592,12 @@
 #define CMDTYPE_FRAME_MARKER           0x0004
 #define CMDTYPE_STREAM_SURFACE_BITS    0x0006
 
+/* Save Session Info PDU Data (2.2.10) */
+#define INFOTYPE_LOGON               0x00000000
+#define INFOTYPE_LOGON_LONG          0x00000001
+#define INFOTYPE_LOGON_PLAINNOTIFY   0x00000002
+#define INFOTYPE_LOGON_EXTENDED_INFO 0x00000003
+
 /* Compression Flags (3.1.8.2.1) */
 /* TODO: to be renamed, not used anywhere */
 #define RDP_MPPC_COMPRESSED            0x20

common/xrdp_client_info.h

@@ -147,6 +147,7 @@ struct xrdp_client_info
     int desktop_cache;
     int use_compact_packets; /* rdp5 smaller packets */
     char client_name[INFO_CLIENT_NAME_BYTES_UTF8];
+    int long_credentials_supported;
     int build;
     int keylayout;
     char username[INFO_CLIENT_MAX_CB_LEN];
@@ -156,6 +157,7 @@ struct xrdp_client_info
     char directory[INFO_CLIENT_MAX_CB_LEN];
     int rdp_compression;
     int rdp_autologin;
+    int rdp_logonnotify;
     int crypt_level; /* 1, 2, 3 = low, medium, high */
     int channels_allowed; /* 0 = no channels 1 = channels */
     int sound_code; /* 1 = leave sound at server */

libxrdp/xrdp_caps.c

@@ -107,6 +107,8 @@ xrdp_caps_process_general(struct xrdp_rdp *self, struct stream *s,
     self->client_info.op1 = extraFlags & NO_BITMAP_COMPRESSION_HDR;
     /* use_compact_packets is pretty much 'use rdp5' */
     self->client_info.use_compact_packets = (extraFlags != 0);
+    /* LONG_CREDENTIALS_SUPPORTED is used when sending session info */
+    self->client_info.long_credentials_supported = (extraFlags & LONG_CREDENTIALS_SUPPORTED) != 0;
     /* op2 is a boolean to use compact bitmap headers in bitmap cache */
     /* set it to same as 'use rdp5' boolean */
     self->client_info.op2 = self->client_info.use_compact_packets;

libxrdp/xrdp_iso.c

@@ -73,6 +73,7 @@ xrdp_iso_create(struct xrdp_mcs *owner, struct trans *trans)
     self->mcs_layer = owner;
     self->trans = trans;
 
+#ifndef VMCONNECT_FORCE
     // See if we're running in vmconnect mode on this connection
     struct xrdp_client_info *client_info = &(self->mcs_layer->sec_layer->rdp_layer->client_info);
     if (client_info->vmconnect && trans->mode != TRANS_MODE_VSOCK)
@@ -83,6 +84,7 @@ xrdp_iso_create(struct xrdp_mcs *owner, struct trans *trans)
             desc);
         client_info->vmconnect = 0;
     }
+#endif
     return self;
 }
 

libxrdp/xrdp_rdp.c

@@ -619,7 +619,7 @@ xrdp_rdp_send_data_from_channel(struct xrdp_rdp *self, struct stream *s,
     pdulen = len;
     dlen = len;
     ctype = 0;
-    clen = len;
+    clen = 0;    /* When not using compression: the compressed length is 0 */
     tocomplen = pdulen - 18;
 
     if (compress && self->client_info.rdp_compression &&
@@ -1683,11 +1683,15 @@ xrdp_rdp_send_session_info(struct xrdp_rdp *self, const char *data,
 
     out_uint8a(s, data, data_bytes);
     s_mark_end(s);
-    LOG_DEVEL(LOG_LEVEL_TRACE, "Sending [MS-RDPBCGR] TS_SAVE_SESSION_INFO_PDU_DATA "
-              "infoType 0x%8.8x, infoData <omitted from log>",
-              *((unsigned int *) data));
-
-    if (xrdp_rdp_send_data(self, s, PDUTYPE2_SAVE_SESSION_INFO) != 0)
+    LOG(LOG_LEVEL_TRACE, "Sending [MS-RDPBCGR] TS_SAVE_SESSION_INFO_PDU_DATA "
+        "infoType 0x%8.8x, infoData <omitted from log> (%u bytes)",
+        *((unsigned int *) data),
+        data_bytes);
+
+    /* [MS-RDPBCGR] sect 3.3.5.10.1 - Sending Save Session Info PDU:
+     * "The contents of this PDU SHOULD NOT be compressed." */
+    if (xrdp_rdp_send_data_from_channel(self, s, PDUTYPE2_SAVE_SESSION_INFO,
+                                        self->mcs_channel, 0) != 0)
     {
         LOG(LOG_LEVEL_ERROR, "Sending [MS-RDPBCGR] TS_SAVE_SESSION_INFO_PDU_DATA failed");
         free_stream(s);

libxrdp/xrdp_sec.c

@@ -448,6 +448,12 @@ xrdp_sec_process_logon_info(struct xrdp_sec *self, struct stream *s)
         }
     }
 
+    if (flags & INFO_LOGONNOTIFY)
+    {
+        LOG_DEVEL(LOG_LEVEL_DEBUG, "[MS-RDPBCGR] TS_INFO_PACKET flag INFO_LOGONNOTIFY found");
+        self->rdp_layer->client_info.rdp_logonnotify = 1;
+    }
+
     if (flags & INFO_COMPRESSION)
     {
         LOG_DEVEL(LOG_LEVEL_DEBUG, "[MS-RDPBCGR] TS_INFO_PACKET flag INFO_COMPRESSION found, "

xrdp/xrdp_mm.c

@@ -3207,6 +3207,106 @@ xrdp_mm_display_server_connect(struct xrdp_mm *self)
     return rv;
 }
 
+/*****************************************************************************/
+static int
+xrdp_mm_send_save_session_info(struct xrdp_mm *self)
+{
+    int rv = 0;
+    int bytes;
+    const char *username;
+    size_t username_len;
+    struct stream *s;
+
+    make_stream(s);
+    init_stream(s, 8192);
+
+    /* Get username */
+    if ((username = xrdp_mm_get_value(self, "username")) == NULL)
+    {
+        username = "???";
+        username_len = 3;
+    }
+    else
+    {
+        username_len = g_strlen(username);
+    }
+    /* Check for overflow */
+    if (username_len > INFO_CLIENT_MAX_CB_LEN - 2)
+    {
+        rv = 1;
+        xrdp_wm_log_msg(self->wm, LOG_LEVEL_ERROR, "Username too big !");
+        goto cleanup;
+    }
+
+    /* [MS-RDPBCGR] sect 3.3.5.10.1 - Sending Save Session Info PDU */
+
+    /* "A logon notification of type INFOTYPE_LOGON or INFOTYPE_LOGON_LONG SHOULD
+     * be sent if the INFO_LOGONNOTIFY flag was set by the client
+     * in the Client Info PDU or if the username or domain used to log on to
+     * the session is different from what was sent in the Client Info PDU." */
+
+    if ((self->wm->client_info->rdp_logonnotify ||
+            g_strcmp(self->wm->client_info->username, username) != 0) && 0)
+    {
+        /* We should send a logon notification */
+        if (!self->wm->client_info->long_credentials_supported)
+        {
+            xrdp_wm_log_msg(self->wm, LOG_LEVEL_DEBUG,
+                            "Sending Session Info 'INFOTYPE_LOGON'");
+            /* infoType */
+            out_uint32_le(s, INFOTYPE_LOGON);
+            /* [MS-RDPBCGR] sect 2.2.10.1.1.1 */
+            out_uint32_le(s, 2);                    /* cbDomain */
+            out_uint8s(s, 52);                      /* Domain (empty) */
+            out_uint32_le(s, username_len + 2);     /* cbUserName */
+            out_utf8_as_utf16_le(s, username,
+                                 username_len);     /* Username */
+            out_uint8s(s, 512 - 2 - username_len);  /* Delimiter + pad */
+            out_uint32_le(s, 0);  /* SessionId */
+        }
+        else
+        {
+            xrdp_wm_log_msg(self->wm, LOG_LEVEL_DEBUG,
+                            "Sending Session Info 'INFOTYPE_LOGON_LONG'");
+            /* infoType */
+            out_uint32_le(s, INFOTYPE_LOGON_LONG);
+            /* [MS-RDPBCGR] sect 2.2.10.1.1.2 */
+            out_uint32_le(s, 0x0001);           /* Version */
+            out_uint32_le(s, 574);              /* Size */
+            out_uint32_le(s, 0);                /* SessionId */
+            out_uint32_le(s, 2);                /* cbDomain */
+            out_uint32_le(s, username_len + 2); /* cbUserName */
+            out_uint8s(s, 558);                 /* Pad */
+            out_uint8s(s, 2);                   /* Domain (empty) */
+            out_utf8_as_utf16_le(s, username,
+                                 username_len); /* Username */
+            out_uint8s(s, 2);                   /* Delimiter */
+        }
+    }
+    else
+    {
+        /* "A logon notification of type INFOTYPE_LOGON_PLAINNOTIFY SHOULD be sent whenever
+         * a notification of type INFOTYPE_LOGON or INFOTYPE_LOGON_LONG would not be sent." */
+
+        xrdp_wm_log_msg(self->wm, LOG_LEVEL_DEBUG,
+                        "Sending Session Info 'INFOTYPE_LOGON_PLAINNOTIFY'");
+
+        /* infoType */
+        out_uint32_le(s, INFOTYPE_LOGON_PLAINNOTIFY);
+        /* [MS-RDPBCGR] sect 2.2.10.1.1.3 */
+        out_uint8s(s, 576); /* Pad */
+    }
+    s_mark_end(s);
+
+    /* send to client */
+    bytes = (int) (s->end - s->data);
+    self->mod->server_session_info(self->mod, s->data, bytes);
+
+cleanup:
+    free_stream(s);
+    return rv;
+}
+
 /**************************************************************************//**
  * Initialise and start the connect sequence
  *
@@ -3532,6 +3632,12 @@ xrdp_mm_connect_sm(struct xrdp_mm *self)
             }
             break;
 
+            case MMCS_SEND_SESSIONINFO:
+            {
+                status = xrdp_mm_send_save_session_info(self);
+            }
+            break;
+
             case MMCS_DONE:
             {
                 /* Shouldn't get here */

xrdp/xrdp_types.h

@@ -350,6 +350,7 @@ enum mm_connect_state
     MMCS_GET_SESSION_FILE_DESCRIPTORS,
     MMCS_CONNECT_TO_DISPLAY_SERVER,
     MMCS_CONNECT_TO_CHANSRV,
+    MMCS_SEND_SESSIONINFO,
     MMCS_DONE
 };